diff --git a/examples/helloworld-tutorial.md b/examples/helloworld-tutorial.md
index 1f2c3f5..8fc4580 100644
--- a/examples/helloworld-tutorial.md
+++ b/examples/helloworld-tutorial.md
@@ -243,7 +243,7 @@ If you have a gRPC GUI client such as [Bloom RPC] you should be able to send req
 
 Or if you use [grpcurl] then you can simply try send requests like this:
 ```
-$ grpcurl -plaintext -import-path ./proto -proto helloworld.proto -d '{"name": "Tonic"}' [::]:50051 helloworld.Greeter/SayHello
+$ grpcurl -plaintext -import-path ./proto -proto helloworld.proto -d '{"name": "Tonic"}' '[::]:50051' helloworld.Greeter/SayHello
 ```
 And receiving responses like this:
 ```